Method and apparatus for making closures



H. E. STOVER EI'AL I METHOD AND APPARATUS FOR MAKING CLOSURES 2 Sheets-Sheet 1 Filed Sept. 10, 1941 l mar Y H m M Ma M H I I a M 0 H0 n Feb. 20, 1945. H. E; STOVER ETAL 2,369,763

METHOD AND APPARATUS FOR MAKING CLOSURES Fi led Sept. 10, 1941 2 Sheet s-Sheet 2 :5 7' 7 2 111- M l J i ATTORNEY Patented Feb. 20, 1.945

METHOD AND APPARATUS FOR. MAKING CLOSURES ration of Delaware Application September 10, 1941, Serial No. 410,256

6 i'llaims.

The present-invention relates to the manufacture of closure caps and more particularly to the manufacture of closure caps having a curled edge or wire bead at the lower part of the skirt thereof.

Closure caps for bottles, jars and the like are used extensively and are sold at a very low price, usually less than one-half a cent each. This price includes thecost of the metal, the lacquer coating, the sealing liner, and the cost of manufacturing and selling. Because of the low price, closures have to be made in quantities on mass production machinery in order to be profitable. Generally, sheets of tin are lithographed or coated and fed to a stamplngmachine which stamps out closure blanks that are automatically delivered to a rolling machine. The rolling machine completes the formation of the metal part of the caps, which are then automatically delivered to a machine that cuts and inserts liners therein. The caps leaving the liner machine pass over an inspection table, through an automatic counter and into a shipping carton; such a group of machines is called a unit or line and is capable of producing caps in large quantities, generally in such quantities that the various lines are frequently idle, a separate line being desirable for each size of cap. Each group of machines forming a line costs several thousand dollars, which is a substantial investment for such a low-priced article. A large volume of a particular closure has to be assured before a manufacturer wi make the investment.

A particularly troublesome problem is that some packers who purchase the caps desire the wire edge of the cap to be rolled outwardly, in which case the lacquer on the inside of the cap is exposed at the bottom thereof. Other packers desire the wire edge to be rolled inwardly to give a uniform color to the outside of the caps; Most packers prefer to have their closures made with an inturned wire edge. However, practically all existing machinery is designed for rolling the edges outwardly because of the difliculty of rolling them inwardly, and because of the cost of the additional equipment required therefor. An entirely different machine and a differently shaped blank have, heretofore, been required for rolling an inturned wire. The flange of the cap tends to buckle in rolling an inturned edge. Accordingly, at least ninety-five percent of the closures are formed with outturned edges in spite of the fact that packers prefer closures with inturned edges. The present invention aims to overcome the above difficulties by a new and improved method and means whereby inturned edge closures may be made as inexpensively as outturned edge closures and with minimum changes in existing equipmentior making outturned edge closures. The invention will enable cap manufacturers to supply either type of closure to customers without increasing materially their investment in equipment.

An object of the present invention is to provide a new and improved method of making inturned edge caps.

Another object of the present invention is to provide a method of making inturned edge and outturned edge closure caps on a single machine.

Another object of the present invention is to provide a rapid and inexpensive method of making inturned edge and outturned edge closure caps on a single rolling machine.

Another object of the present invention is to provide a new and improved means for forming a bead on a closure cap.

Another object of the present inventionis to iovide a new and improved means for starting the formation of a bead on a closure cap.

Other and further objects of the invention will be obviousupon an understanding of the illustrative embodiment about to be described, or will be indicated in the appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.

A preferred embodiment of the invention has been chosen for purposes of illustration and description and is shown in the accompanying drawings, forming a part of the specification, wherein Fig. 1 is a fragmentary sectional View illustrating ,a forming die which may be used with the pi esent invention for forming the closure blank;

Fig. 2 is a diagrammatic sectional View illustrating the relative heights of closure cap blanks which may be manufactured and used with the present invention;

Figs. 2a, 2b and 2c are views, partly in section, of types of finished closure caps which are adapted to be made by the present method and device;

Fig. 3 is a side view, partly broken away, illustrating one type of closure cap fabricating machine adapted tobe used with the present method;

Fig. 4 is an enlarged fragmentary sectional view illustrating curling or wiring tools with a closure cap in position for forming an inturned bead on the cap;

Fig. 5 is an enlarged fragmentary sectional view illustrating the curling or wiring tools at r 2,869,768

shown in Fig. i with a closure cap in position for forming an outturned head on the cap;

Fig. 6 is a diagrammatic view illustrating the relation of a curling or wiring member, a chuck. and a closure cap blank at the start of the wiring operation;

Fig. 7 is a diagrammatic view illustrating a developed curling or wiring member adapted to be used for forming a head on a closure cap;

Fig. 7a is a fragmentary top plan view of the wiringmember at the entrance end thereof;

Fig. 8 is an end view of the device shown in Fig. 7;

Figs. 9, 10 and 11 are sectional views along the lines 9--9, Ill-l0, and li---ll, respectively, of Fig. 7;

Fig. 12 is a fragmentary view illustrating a modified form of entrance portion for a curling or wiring die; and

Fig. 13 is an end view of the device shown Fig. 12.

Referring again to the drawings illustrating a preferred embodiment of the invention and one way of practicing the method there is shown in Fig. 1 a blank forming die i adapted to cooperate with any suitable punch member (not shown) to form substantially hat-shaped blanks t for use in practicing the present method. The punch member moves in and out of the recess 5 in the die member i to draw or form the metal of a closure blank into the desired substantially hat-shaped form. The height of the crown or skirt i of a blank andthe width of the outwardiy projecting flange 8 thereon are dependent upon the distance that the punch member moves into the recess 5 of the die member I. Where the punch member moves a relatively short distance into the die recess 5. a hat-shaped blank will be formed which has a relatively low height crown i and a wide brim portion 8. In instances where the punch member moves a greater distance into the die recess 5 the hat-shaped blank will have a greater height of crown l and a brim portion ll of less width (Fig. 2). With the present method, the height of the crown of the blank is an important dimension. This may be done without changing the sizes of the blanks stamped from the sheet and without changing the lithographed designs thereon.

While one punch and die machine may be utilized for forming closure blanks with a high crown and another punch and die member may be utilized for forming closure blanks having a relatively low crown, such an arrangement would require two stamping machines to form the blanks. With the present method it is preferred to form both tall and short closure blanks with a single punch and die machine. By using a single stamping press the cost of an additional press is eliminated and the changes required are minimized. In Fig. 1 the punch and die are illustrated set up for the manufacture of closure blanks having a relatively short height of crown. That is, a die pad i3 is retained in spaced position from the bottom of the die recess by a spacer or washer member l4 so that the die pad 43 limits downward movement of the punch member into the die recess 5. This limitation in downward movement of the punch member results in the formation of a closure blank having a relatively low height of crown. When it is desired to manufacture a hat-shaped closure cap blank having a relatively tall crown, the spacer or washer member I may be removed from the die recess 5 so that the die pad l3 may rest at the bottom of the die recess I. The punch mem ber may then move farther into the die recess 5. This results in the formation of a closure cap blank having a tall crown I0 and a brim portion I l of less width than in instances where the spacer member I4 is utilized. Thus, blanks with different heights of crowns may be manufactured with a single stamping machine without changing the lithographed designs on the sheets of metal fed to the press, as the size of the discs stamped from the sheets are the same in each instance.

Fig. 2 illustrates diagrammatically the relative proportions of hat-shaped closure blanks formed with and without the use of the spacer member Id. The closure blank shown in solid lines has a relatively short height crown and a wide flange or brim portion; ithis closure blank will be formed by utilizing the spacer member i4 and may be utilized in the formation of a closure cap having an lnturned head. A closure cap blank formed without the use of the spacer member I4 is illustrated by the dotted lines of Fig. 2; this latter closure blank may be utilized in the manufacture of a. closure cap having an outtumed bead or wire edge at the lower portion thereof. The spacer or washer member l4 may be easily and rapidly placed in position beneath the die pad l3 or removed therefrom.

In Fig. 3 there is illustrated a machine for manufacturing closure caps from the blanks pre-- viously described. This type of machine may be substantially like that illustrated and described in Charles Hammer Patent No. 1,671,990. A rotating member 9 is provided to rotate on a. mounting II. A driving gear (not shown) meshes with the gear teeth on the periphery of the rotating member 9 to drive it at a desired speed. A plurality of chucks i! are rotatably mounted in suitable bearings E5 on the member 9. A stationary member I8 is provided adjacent the rotating member 9 and has therein a plural ity of cap forming elements or tools 20, 22 and 23. While asingle tool or member could be provided for performing the several operations on the closure, for convenience three elements are preferred. The element 20 is primarily useful in forming the wire edge. The element 22 in the middle is primarily useful in forming a thread. The element 23 is primarily useful in forming the knurls. In operation, the rotating member 9 carries the chucks I], with closure blanks thereon, around the stationary member i8 and in engagement with the elements 20, 22 and 231. While the sequence of the several operations may be varied it is preferred to have the knurling tool in engagement with the blank during the several operations in order to prevent slippage. The wiring is preferably performed prior to the threading operation. The groove for wiring in the tool 20 is specially constructed, as will be described hereinafter, to enable it to perform the difficult operation of turning the edge of the cap into an inturned wire edge. In some instances it may be desirable to manufacture closure caps without an externally visible knurl at the upper part thereof; in such event the knurls on the tool 23 may be omitted and the closure blanks driven by suitable knurled or roughened surfaces carried only on the chucks H.

The manufacture of an inturned bead or wire edge on a closure blank will now be described as it is the more difiicult operation. In Fig. 4 there is illustrated a fragmentary sectional view of a chuck I! for moving or rolling a closure blank about the stationary member i9 and along illustrated in solid lines in Fig. 2, is utilized.

When the blank is automatically picked upby a chuck II the outwardly projecting flange portion at the bottom of the blank projects outwardly into a wiring or curling groove 25 on the elongated curling or wiring tool 20. The groove 25 varies in depth, being of the greatest depth at its entrance end and-of smallest depth at its I exit end. In the preferred embodiment, as shown more particularly at 35 in Figs. 7 and 7a, the groove flares outwardly in depth and width adjacent the entrance to thewiring tool. Preferably the total length of the wiring groove is equal to approximately three times the circumference of the cap. The flared mouth portion 35 decreases gradually and evenly in depth and width to a point where it is substantially uniform for a distance equal to the circumference of the cap, as shown at 39. The groove then further decreases in depth, preferably without decreasing the width, at the entrance to the second stage where it remains uniform for an additional distance equal to the circumference of the blank. In the final or third stage the groove substantially forms the wire or bead into its finished shape. The size of the groove will determine the size of the bead and the extent to which it is curled. It will be understood also that a greater or less number of steps may be used in the formation of the bead. The flared entrance 35 at the entrance to the groove in the first stage is particularly helpful in the formation of an inturned wire, as the wiring or curling operation is quite dimicult to start. The formation of an outtinned wire is greatly facilitated because of the curvature already formed at the junction of the skirt and flange of the cap blank. It will be noted that a. closure blank with a short height crown presents its outwardly extending flange to the flared portion 35 at the entrance of the initial wiring groove. Since the flange of the closure blank cannot turn in the direction toward the cover of the blank, it must turn in the opposite direction as shown in Fig. 4. The gradual flare at the entrance is such as to cause it to so turn. The gradual reduction in three steps of the depth of the wiring groove forms the flange into an inturned bead in successive easy stages. The element 23 is effective in forming knurls in the upper part of the blank and in a successive step the element 22 may form a screw thread or other holding means thereon. Preferably the side 28 of the wiring groove which acts as a support for the flange of a short height closure cap is rounded at its inner free end 3| so that it has a radius substantially the same as that at the junction of the flange and skirt of the closure.'

This has been found to facilitate smooth and even curling of the cap flange portion into a bead.

Fig. 5 illustrates a chuck II of the rolling machine with a tall skirt closure. blank thereon adapted to have an outturned bead or wire formed from the flange H. In this instance the hat-shaped closure blank is of suitable height so that the outwardly extending flange portion H rests against the opposite side 29 of the wiring groove 25. As the chuck Il rotates and moves the flange it alon the wiring groove, the gradually decreasing depth of the wiring groove will cause the flange I l to curl upwardly, as indicated by the dotted lines in Fig. 5.

By thus utilizing a hat-shaped closure cap blank having a relatively short height crown, the outwardly extending flange portion thereon will be in contact with the side of a wiring groove nearest the cover of the blank. The flange in this instance will be curled away from the cover of the blank and inwardly to form an inturned bead (Fig, 2a). When a hat-shaped closure cap blank having a relatively tall height crown is placed on a chuck of the same machine, the outwardly extending flange will rest against the side of the wiring groove remote from the cover of the blank and will be curled toward the cover of the blank and inwardly to form an outturned bead as it moves along the wiring groove of diminishing depth. As previously brought out, the height of the hat-shaped'closure may be easily varied by inserting or removing the washer It shown behind the die pad 13 in Fig. 1. The thickness of the washer l4 should be substantially equal to the width of the wiring groove minus the thickness of the material from which the closure blank is to be formed. For example, if the diameter of the wiring groove is .062" and the thickness of the closure cap material is .010", the thickness of the washer l4 should be about .052". It will be understood that the beaded edge may be formed on closure blanks that are to have a continuous screw thread formed in the skirt thereof or it may be easily formed on any other type of closure cap. For example, after either an inturned or outturned. wire is formed it may be struck inwardly to form lug portions, as shown in Fig. 20 for engaging with the projecting ledge on a container designed for this type of cap.

In order to facilitate curling'the flange'of a hat-shaped closure blank into an inturned bead it is desirable that the depth at entrance to the curling or wiring stage decrease gradually until it merges into the subsequent portion of the curling groove. Fig. 6 illustrates diagrammatically a chuck l1, closure blank 32, and portion of a curling section 34. The entrance portion 35 of the curling groove 25 has a gently flaring crosssection (note the dotted wall portion 31) adapted to commence the curling of the flange gradually and not abruptly.

As pointed out above, the rolling of an inturned wire presents difliculties. The groove described above and illustrated in Figs'.'7 to 11 has been found to produce good results. A modifled construction particularly useful in connection with rolling an inturned wire edge and also helpful in rolling an outturned .wire edge is illustrated in Figs. 12 and 13. A roller 40 is provided adjacent the entrance to the curling groove 25a. The roller has an annular groove in the outer periphery thereof. The flange of the cap blank engages the roller prior to engaging the groove. The roller by reason of the reduced friction facilitates entrance of the cap flange into the curling groove. The groove channel 4! of the roller is in line with the curling groove 25a and forms a part of the gradually flared entrance portion to the curling groove. The roller is particularly helpful in preventing a buckle, wrinkle or bump at the commencement of the wire forming operation.

In the operation of the method and device a stamping machine is provided for stamping out closures from sheets of lithographed metal. The dies for forming the cap blanks are preferably in accord with that illustrated in Fig. 1 whereby the height of the blanks may be changed by the use of a shim I4 located behind the member i3. From the stamping machine the cap blanks are automatically delivered to a rolling machine such as that illustrated diagrammatically in Fig. 3. Suitable automatic conveyors lead from the rolling machine to a machine for inserting liners into the closures. The finished closure caps are delivered to an inspection table and to a counter from which they pass to shipping containers. This is what is commonly known as a line or a unit for making closures. Closures may be made at a very rapid rate and at a low manufacturing cost. An inspector may operate an entire unit. If the manufacturer desires to deliver closure caps having an inturned wire edge it is merely necessary to insert the shims or washers H in the stamping machines, which is a very simple operation, and the closures come out of the line with inturned wire edges. If the shims are removed the closures comin out of the line have outturned wire edges. In this way no additional equipment is required to deliver both inturned and outturned edge closure caps from a line. The changes required to be made to a stamping machine are relatively simple and the time required for making them is not substantial. The changes required in the rolling machine pertain to the grooving element and hence could be made without substantial expense, as the rolling machines have to be repaired from time to time in any event. It is not believed necessary to describe at this point the movement of the cap blank through the rolling machine and along the groove as this has already been explained in detail herein. It might be observed that the rollin machine is adapted to receive closures and fabricate them at the rate they are stamped and likewise the liner inserting machine is adapted to insert liners as fast as the rolling machine fabricates closures. The rolling machine may be adapted to provide any desired type of holding means in the caps; for example, a screw thread or a screw lug (Figs. 2a, 2b and 20).

It will be seen that the present invention provides a new and improved method for forming either outturned or inturned edges on closure caps. Both inturned and outturned edges may be formed in a single cap manufacturing unit or line with minor changes in the equipment. As a result cap manufacturers may supply to their customers either inturned or outturned edge closures without increasing materially their investment for equipment. The inturned edge closures may be supplied without additional cost and without difficulty. The usual expensive machinery commonly required, such as dial presses for bumping operations, is eliminated. Since the units for making outturned edge closure caps have more capacity than is ordinarily required, and hence are idle for substantial periods, the units may be used during these idle periods for making inturned edge caps. Greater flexibility is afforded in cap factories and the manufacture of inturned edge caps will be facilitated. Y

As various changes may be made in the form, construction and arrangement of the parts herein without departing from the scope and spirit of the invention and without sacrificing any of its advantages, it is to be understood that all matter herein isto be interpreted as illustrative and not in a limiting sense.

Having thus described our invention, we claim:

1. Means for forming a wire edge on flanged closure cap blanks comprising, in combination, a curling groove made up of a plurality of stages of substantial length, to progressively curl the flange of a flanged closure cap blank into a wire edge, each of said stages having a' portion of uniform depth, which is less than the width of the flange, the entrance portion to the curling groove of one of said stages being flared outwardly to form a portion of relatively greater width and depth than the rest of said curling groove whereby entry of the edge of the flanged closure cap lank into said curling groove is facilitated, a grooved roller positioned adjacent the entrance to the groove to engage the flange of the blank and initially curl it and a plurality of chucks for carrying the. flanged closure cap blanks thereon with the flanges of said blanks projecting into said curling groove, said chucks being arranged to roll said flange progressively past said roller and along said curling groove.

2. Means for forming a wire edge on flanged closure cap blanks comprising, in combination, a curling groove comprising a plurality of curling stages arranged in series and each having substantially the same width throughout the major part of the length thereof, the grooves of each of said stages having a depth less than the Width of the flange of the closure blank and diminishing relatively rapidly in depth adjacent the entrance portion thereof, the curling grooves of said stages cooperating to progressively curl the flange of a closure cap blank into a wire edge and a grooved roller positioned adjacent the entrance to the first of said stages to engage the flange of the blank and guide it into the curling groove.

53. Means for forming a head on a flanged closure cap blank comprising, in combination, a curling groove comprising a plurality of curling stages arranged in series and the groove in each stage decreasin cross-section to progressively curl the edge of the flange of the closure cap blank into a head, a roller positioned adjacent the entrance to the groove of one of said stages to engage and initially curl said flange thereby to facilitate entry of the edge of a closure cap blank into said curling groove and initial curling thereof and a chuck adapted to fit into the closure blank and to roll the flange thereof past said roller and along said groove to form a head from the flange thereof,

4. Means adapted to receive and curl the flange of a flanged closure cap blank comprising, in combination, a member having a groove therein for receiving and curling said flange, a roller positioned adjacent the entrance to said groove to engage said flange, initially curl it and guide the flange into said groove and a chuck adapted to fit into the closure blank and to roll the flange thereof past said roller and along said groove to form a head from the flange thereof.

5. The improvement in the manufacture of beaded closure caps in a closure-forming machine having a bead rolling groove with a substantially U-shaped cross section adapted to form an outturned bead from the flange of a hat-shaped blank by rolling the flange against the bottom and the far side of the U-shaped groove which method comprises selecting a hat-shaped blank having a height sufficiently less than that required for making a closure with an out-turned bead to brin the flange of the blank against the side of the groove nearest the cover of the closure, delivering said closure blank of reduced height to said rolling machine, holding said flange against said side of the groove, rolling said flange against the bottom of the groove and against the opposite side thereof to form an inturned bead, and rolling said head to extend below the bottom of the blank.

6. The improvement in the manufacture of beaded closure caps in a closure-forming machine having a bead rolling groove with a substantially U-shaped cross section and. having a plurality of stages of different depths adapted to form an outturned bead from the flange of a hat-shaped blank by rolling the flange against the bottom and the far side of the U-shaped groove which method comprises selecting a hat-shaped blank having a height sufficiently less than that required for making a closure with an outturned bead to brin the flange of the blank against the side of the groove nearest the cover of the closure.

' delivering said closure blank of reduced height to said rolling machine, holding said flange 

